This occurs when the body’s immune system mistakenly identifies a food as a threat and releases chemicals, such as histamine, in response. It is the release of these chemicals that causes the allergic symptoms.
The symptoms of a true food allergy can come on rapidly and can occur after eating very small amounts of the food. Symptoms may include nettle rash (otherwise known as hives or urticaria) anywhere on the body, or a tingling or itchy feeling in the mouth.
If you suspect you are allergic to a food, report this to your GP who can refer you to an allergy clinic for testing if necessary. If the tests prove negative, the allergist may consider whether your symptoms have some other cause, such as an intolerance.
Once a culprit food is identified, it is important to be vigilant to avoid that food. Some people with food allergy suffer symptoms that are severe – a condition known as anaphylaxis. Although anaphylaxis to onion and/or garlic is believed to be very rare, you should ask your doctor or allergy specialist what symptoms are likely to occur in your case. Always carry any prescribed treatment with you.